The invention relates generally to wheelchairs and related devices and in particular to a wheelchair safety device. For those who use wheelchairs, transferring into and out of the wheelchair can be very nerve-wracking. Although all modern wheelchairs have brakes, they are inadequate to prevent the wheelchair from sliding across the floor with the brakes engaged, or tipping over and falling forward. Such events occur more frequently with larger, heavier users and endanger their ability to live independently. Ideally, a mechanism would be installed which counters the user's size and weight, maintaining the wheelchair in a stable position, and ensuring that the user may enter and exit the wheelchair without difficulty or assistance. A wheelchair safety device, which transfers the weight of the entering or exiting user into a brake and stop against the rear wheel and floor, would resolve this problem.